diff --git a/domain/index.go b/domain/index.go
index 1406dbab5..11e91c78c 100644
--- a/domain/index.go
+++ b/domain/index.go
@@ -1,5 +1,7 @@
 package domain
 
+import "github.com/deluan/gosonic/utils"
+
 type ArtistInfo struct {
 	ArtistId string
 	Artist   string
@@ -7,7 +9,14 @@ type ArtistInfo struct {
 
 type ArtistIndex struct {
 	Id      string
-	Artists []ArtistInfo
+	Artists ArtistInfos
+}
+
+type ArtistInfos []ArtistInfo
+func (a ArtistInfos) Len() int { return len(a) }
+func (a ArtistInfos) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a ArtistInfos) Less(i, j int) bool {
+	return utils.NoArticle(a[i].Artist) < utils.NoArticle(a[j].Artist)
 }
 
 type ArtistIndexes []ArtistIndex
diff --git a/domain/mediafile.go b/domain/mediafile.go
index ee26d25da..658e88ad4 100644
--- a/domain/mediafile.go
+++ b/domain/mediafile.go
@@ -33,6 +33,11 @@ func (mf *MediaFile) ContentType() string {
 }
 
 type MediaFiles []MediaFile
+func (a MediaFiles) Len() int { return len(a) }
+func (a MediaFiles) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a MediaFiles) Less(i, j int) bool {
+	return (a[i].DiscNumber * 1000 + a[i].TrackNumber) < (a[j].DiscNumber * 1000 + a[j].TrackNumber)
+}
 
 type MediaFileRepository interface {
 	BaseRepository
diff --git a/persistence/index_repository.go b/persistence/index_repository.go
index 664e247dd..2f2c08188 100644
--- a/persistence/index_repository.go
+++ b/persistence/index_repository.go
@@ -3,7 +3,6 @@ package persistence
 import (
 	"errors"
 	"github.com/deluan/gosonic/domain"
-	"github.com/deluan/gosonic/utils"
 	"sort"
 )
 
@@ -21,7 +20,7 @@ func (r *artistIndexRepository) Put(m *domain.ArtistIndex) error {
 	if m.Id == "" {
 		return errors.New("Id is not set")
 	}
-	sort.Sort(byArtistName(m.Artists))
+	sort.Sort(m.Artists)
 	return r.saveOrUpdate(m.Id, m)
 }
 
@@ -37,16 +36,4 @@ func (r *artistIndexRepository) GetAll() (domain.ArtistIndexes, error) {
 	return indices, err
 }
 
-type byArtistName []domain.ArtistInfo
-
-func (a byArtistName) Len() int {
-	return len(a)
-}
-func (a byArtistName) Swap(i, j int) {
-	a[i], a[j] = a[j], a[i]
-}
-func (a byArtistName) Less(i, j int) bool {
-	return utils.NoArticle(a[i].Artist) < utils.NoArticle(a[j].Artist)
-}
-
 var _ domain.ArtistIndexRepository = (*artistIndexRepository)(nil)
\ No newline at end of file
diff --git a/persistence/mediafile_repository.go b/persistence/mediafile_repository.go
index 390506e22..3a2aa9ae0 100644
--- a/persistence/mediafile_repository.go
+++ b/persistence/mediafile_repository.go
@@ -27,20 +27,8 @@ func (r *mediaFileRepository) Get(id string) (*domain.MediaFile, error) {
 func (r *mediaFileRepository) FindByAlbum(albumId string) (domain.MediaFiles, error) {
 	var mfs = make(domain.MediaFiles, 0)
 	err := r.loadChildren("album", albumId, &mfs, "", false)
-	sort.Sort(byTrackNumber(mfs))
+	sort.Sort(mfs)
 	return mfs, err
 }
 
-type byTrackNumber domain.MediaFiles
-
-func (a byTrackNumber) Len() int {
-	return len(a)
-}
-func (a byTrackNumber) Swap(i, j int) {
-	a[i], a[j] = a[j], a[i]
-}
-func (a byTrackNumber) Less(i, j int) bool {
-	return (a[i].DiscNumber * 1000 + a[i].TrackNumber) < (a[j].DiscNumber * 1000 + a[j].TrackNumber)
-}
-
 var _ domain.MediaFileRepository = (*mediaFileRepository)(nil)
\ No newline at end of file